The present subject matter relates generally to misting and atomization systems and methods that may be used to spray liquids, such as water, paint, and others.
There are various misting or spraying methods for various liquids. Each has its own drawbacks and challenges. Many of the problems with currently available systems and methods are well illustrated with reference to conventional paint sprayers or mist cooling atomizers. Accordingly, much of the present disclosure references these applications. However, it is understood that the teachings provided herein with respect to paint and mist cooling are applicable across a great range of fluids.
A common method for applying paint to a surface involves the use of a cylindrically shaped paint roller or brush dipped into a supply of paint. Whereas these methods provide adequate penetration of the paint to a surface, these methods are both time consuming and messy.
In contrast, spray methods have been developed that allow for a faster painting process, but these methods have their own disadvantages. Various spray painting systems have been proposed where the paint is delivered under power to a paint applicator. Unfortunately, in these systems the paint applicator has a tendency to become clogged, thereby rendering the system useless and requiring the user to buy a replacement device.
In addition, the current spray paint devices do not provide paint to a substrate in a controlled manner such that the paint is delivered at the proper rate. In order to achieve optimal atomization extremely high pressures must be used, forcing the equipment to spray over five gallons an hour in common working conditions. Only a very small percentage of highly trained technicians are capable of applying so great a torrent of paint accurately. Further, paint is often distributed with an improper uniformity or irregularity to a paint surface. Moreover, minor variations in paint viscosity by dilution produces unpredictable spray quality with the present devices. As a result, fine-tuning the spray by measuring viscosity is difficult with the present devices.
Further, instead of providing an even distribution of spray over a wide spray pattern, current spray devices may force spray through a tiny hole to provide a spray pattern that is uneven. More paint is delivered in the center of the spray than at the edges. In factory settings where a wide swath of paint is desired, complex set-ups of numerous nozzles must be designed and fine-tuned in their proximity one to another in order to approximate even distribution. And of course, if one of the nozzles clogs, the entire paint session is compromised. Additionally, the high pressures used in such systems rapidly wear out the nozzle, ruining the spray quality, and requiring frequent monitoring and replacement.
Another serious drawback to almost all conventional paint sprayers is overspray. For example, a fog of paint particles is produced by the atomization process that fills up whole rooms with tiny droplets that stick on any surface. Overspray is also dangerous: most spray paint must be applied while wearing a mask to prevent inhalation of the paint droplets, which can be life-threatening. In a factory setting, spray paint is usually applied in sealed boxes or small rooms with special blowers for ventilation. Spray paint applied in private homes demands protecting every surface where paint is not wanted by covering it with airtight layers of plastic sheeting. Even adjoining rooms must be protected this way. Overspray constitutes wasted paint that can often reach over 30% of all paint sprayed, a considerable loss, especially considering the considerable cost of the paint and cleaning up.
A further drawback of conventional spray paint methods is bounceback. Specifically, the atomization process frequently creates a high-speed blast of air moving around the paint droplets. The air blast air flow reflects off the application target and pushes other droplets on their way to the target away from the target completely. As a side effect of bounceback, many current paint sprayers are incapable of filling small cracks under 2 mm or so width with any paint to any depth. A further drawback to the high air flow causing the bounceback is that it blows on the droplets at great speed and can dry them out before they hit the target.
Moreover, many of the powered painting systems are complicated with numerous parts and, therefore, difficult to clean and repair. Cleanup of a sprayer, even the most expensive ones, can take hours and even require soaking overnight.
Changing paint colors in the middle of an application project is not an option for conventional equipment. Moreover, typical conventional systems are only suited for one type of liquid, namely, paint. Therefore, a user would need to purchase an entirely different device to supply other liquids, such as insecticides or air fresheners.
Further, the current powered painting systems require a substantial amount of energy, high pressure, electrical cords, battery packs, or pumps in order to supply the paint to a surface.
Cooling by water evaporation is another common application of atomization devices that presents its own range of challenges. Inexpensive cooling mists fail to atomize well, and produce sprays that are both uncomfortable and inefficient. For example, the large droplets produced by these low-cost atomization devices are so uncomfortable that it is virtually impossible to sit directly in the atomization path and air flow path. Second, the conventional atomization devices produce particles of a size so large that many of them never evaporate at all, thus failing to produce a cooling effect.
More expensive mist cooling systems do produce quality atomization. However, the high pressures required to produce the atomization have an undesired effect of raising the humidity in the environment of the device. For example, the water flow from a minimum four nozzle installation is rarely less than 0.116 gallons per minute and usually more than that—an amount of water so great that in one minute the device will increase the humidity of almost 2,000 cubic feet of air from 50% to 70% or more humidity. At such levels the evaporative cooling system becomes remarkably less efficient. In addition, this added humidity is uncomfortable to the users of the system, which typically use the system in order to cool themselves. In other words, the conventional systems deny the users the direct benefit of the cooling and greatly increase the overall humidity.
Further disadvantages of typical cooling systems include the high cost of the device relative to the minimal cooling they produce. In addition, the cooling devices typically produce uncomfortably large amounts of noise up to more than 60 decibels from the operation of the compressor, from the operation of fans large enough to handle the high levels of mist, and from the quite loud hissing of the nozzles. Further, the current cooling devices typically only produce mist from one spray nozzle at a time, necessitating multiple nozzles for increased cooling. Finally, because the atomization concentrates all the droplets into a very small area around the one tiny point from which they are all sprayed, the best atomizers have an additional drawback of creating a heavy fog which is distracting, uncomfortable, and easily re-condenses on smooth surfaces.
Accordingly, there is a need for a device to supply atomization in a consistent manner, quietly, with a relatively simple structure and assembly, such that the system leads to easy maintenance and cleaning, as well as adaptability during use.